Air blowing tool for heat-shrinkable packing material

ABSTRACT

An air blowing tool includes a connecting pipe ( 1 ) and an air blowing head ( 2 ). The air blowing head includes an inner wall ( 22 ), and an outer wall ( 21 ). An annular passage ( 24 ) is defined between the inner and outer walls. The inner wall encloses and defines a heating space ( 23 ) for accommodating a package ( 3 ) to be heated. A plurality of evenly distributed outlets ( 221 ) is defined in the inner wall. Each outlet is defined at an acute angle relative to the annular passage. Each outlet is progressively flared such that a cross-sectional area of the outlet at the heating space is greater than a cross-sectional area of the outlet at the annular passage.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a co-pending application of three otherpatent applications all entitled AIR BLOWING TOOL FOR HEAT-SHRINKABLEPACKING MATERIAL, invented by the same inventors of the presentinvention, filed on the same date as the present application, andassigned to the same assignee as that of the present application,namely, Hon Hai Precision Ind. Co. Ltd.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to heating devices forheat-shrinkable packing material, and particularly to devices utilizingblowing of hot air over such packing material.

[0004] 2. Description of the Related Art

[0005] Many products including optical communication components are verysensitive to environmental contamination, such as from dust or water. Itis important to provide secure protection for such products during theirtransportation.

[0006] The usual way to protect products such as optoelectroniccomponents is to pack them in plastic film. The plastic film isgenerally heat-shrinkable, and is first applied to loosely envelop theoptoelectronic component. Then, hot air is blown on the film. Onceheated, the film shrinks to tightly pack the component. Conventionaldevices for heating the plastic film cannot blow hot air onto theplastic film uniformly. As a result blisters may be formed in the film,thus diminishing the aesthetic appearance of the product. Even worse,the film may break and expose the component to contamination.

[0007] In view of the above, there is a need for a tool which can blowhot air evenly onto the heat-shrinkable plastic film, to ensure thatproducts such as optoelectronic components are properly protected andhave an attractive appearance.

SUMMARY OF THE INVENTION

[0008] Therefore, an object of the present invention is to provide anair blowing tool which can blow heated air evenly onto heat-shrinkablematerial used for packing products such as optoelectronic components.

[0009] To achieve the above object, an air blowing tool of the presentinvention comprises a connecting pipe and an air blowing head. Theconnecting pipe has a first wide passage and a second narrow passagedefined therein. The air blowing head includes an inner wall and anouter wall. An annular passage is defined between the inner and outerwalls. The inner wall encloses and defines a heating space foraccommodating a package to be heated. A plurality of evenly distributedoutlets is defined in the inner wall. Each outlet is defined at an acuteangle relative to the annular passage. Each outlet is progressivelyflared such that a cross-sectional area of the outlet at the heatingspace is greater than a cross-sectional area of the outlet at theannular passage.

[0010] Other objects, advantages and novel features of the inventionwill become more apparent from the following detailed description whentaken in conjunction with the accompany drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a cross-sectional view of an air blowing tool for aheating device for heat-shrinkable packing material in accordance withthe present invention; and

[0012]FIG. 2 is a perspective view of the air blowing tool of FIG. 1,together with a package enveloped by heat-shrinkable plastic film placedin a space within an air blowing head of the air blowing tool.

DETAILED DESCRIPTION OF THE INVENTION

[0013]FIG. 1 is a cross-sectional view of an air blowing tool for aheating device for heat-shrinkable packing material in accordance withthe present invention. The air blowing tool comprises a connecting pipe1 and an annular air blowing head 2. The connecting pipe 1 comprises afirst pipe 11, and a second pipe 12 integrally connected with the firstpipe 11. The first pipe 11 has a first passage 111 connecting with anexternal blower (not shown) of the heating device (not shown). The firstpipe 11 receives heated air from the blower. The second pipe 12 has asecond passage 121. A diameter of the second passage 121 is less than adiameter of the first passage 111, so that hot air from the firstpassage 111 flows faster in the second passage 121.

[0014] The blowing head 2 connects with the second pipe 12 of theconnecting pipe 1. The blowing head 2 comprises an outer wall 21 and aninner wall 22. The inner wall 22 encircles and defines a round heatingspace 23 therein. An annular passage 24 is defined in the blowing head 2between the outer wall 21 and the inner wall 22. The second passage 121of the connecting pipe 1 communicates with the annular passage 24 at anacute angle, to allow maximal airflow from the second passage 121 to theannular passage 24. A plurality of evenly distributed outlets 221 isdefined in the inner wall 22. In the preferred embodiment, there areeight outlets 221. Each outlet 221 communicates with the annular passage24 and the heating space 23. Each outlet 221 is defined at an acuteangle relative to the annular passage 24, such that a direction of airflow within each outlet 221 is generally in compatible alignment with adirection of circulating air flow within the annular passage 24. Thusair flow within the annular passage 24 can easily enter the outlets 221and flow therethrough to reach the heating space 23. Each outlet 221 hasan arcuate longitudinal profile, such that air flow therewithin isguided toward a center portion of the heating space 23. Each outlet 221is progressively flared such that a cross-sectional area of the outlet221 at the heating space 23 is greater than a cross-sectional area ofthe outlet 221 at the annular passage 24. Thus hot air can flowuniformly and at a steady low speed into the heating space 23 via theoutlets 221.

[0015] Referring also to FIG. 2, in use, a package 3 comprises anoptoelectronic component (not shown) enveloped by a heat-shrinkableplastic film 31. The package 3 is put in the heating space 23 of theblowing head 2. Hot air generated from the blower (not shown) flows intothe connecting pipe 1. A speed and a temperature of the hot air aredetermined by the characteristics of the packing film and of thecomponent. Such characteristics include a thickness and a composition ofthe film, and a size of the component. The hot air enters the annularpassage 24 from the connecting pipe 1, and then enters the heating space23 via the outlets 221. The film 31 is thereby heated up uniformly, andshrinks to be tightly attached onto surfaces of the package 3.

[0016] Because the outlets 221 are evenly distributed around the innerwall 22, and because the orientation of the outlets 221 is compatiblewith the direction of flow of hot air in the annular passage 24, the hotair can flow into the outlets 221 easily and quickly. In addition,because the outlets 221 are arcuate in profile, and because they areflared, the hot air is slowly and uniformly distributed into the heatingspace 23. Furthermore, because the heating space 23 has a circularconfiguration, the hot air exiting the outlets 221 forms a circular pathof air flow around the package 3 in the heating space 23. Therefore theplastic film 31 is heated evenly, and shrinks evenly to encase thecomponent tightly, uniformly, and in an aesthetically pleasing form.

[0017] It should be understood that various changes and modifications tothe presently preferred embodiment described herein will be apparent tothose skilled in the art. Such changes and modifications may be madewithout departing from the spirit and scope of the present invention andwithout diminishing the present invention's advantages. Thus, it isintended that such changes and modifications be covered by the appendedclaims.

1. A tool for blowing hot air onto heat-shrinkable packing material, thetool comprising: a connecting pipe adapted to be connected with a hotair blower; and an annular air blowing head comprising an outer wall, aninner wall, and an annular passage defined between the outer and innerwalls and communicating with the connecting pipe, a circular heatingspace being defined inwardly from the inner wall and adapted forreceiving a package having heat-shrinkable packing material, the headfurther comprising a plurality of outlets defined in the inner wall,each outlet communicating with the annular passage and with the heatingspace; wherein each outlet is defined at an acute angle relative to theannular passage of the head such that a direction of air flow in theoutlet is generally in compatible alignment with a direction ofcirculating air flow within the annular passage; and each outlet isprogressively flared such that a cross-sectional area of the outlet atthe heating space is greater than a cross-sectional area of the outletat the annular passage.
 2. The tool as described in claim 1, whereineach outlet has a generally arcuate configuration.
 3. The tool asdescribed in claim 1, wherein the outlets are evenly distributed aroundthe inner wall of the head.
 4. The tool as described in claim 3, whereinthere are eight outlets.
 5. The tool as described in claim 1, whereinthe connecting pipe includes a first pipe and a second pipe, the firstpipe has a first passage, the second pipe has a second passage, adiameter of the second passage is less than a diameter of the firstpassage, and the annular passage of the head communicates with thesecond passage.
 6. The tool as described in claim 5, wherein the secondpassage communicates with the annular passage at an acute angle.
 7. Ahot air blowing tool, comprising: a pipe adapted for receiving hot airflow; and an air blowing head integrally formed with the pipe, the headcomprising an outer wall, an inner wall and an air passage definedbetween the outer and inner walls and in communication with the pipe, aplurality of outlets being defined in the inner wall, each outletcommunicating with the air passage and a space surrounded by the innerwall.
 8. The tool as described in claim 7, wherein the head has anannular configuration, the air passage is annular, and each outlet isoriented at an acute angle relative to a direction of air flow withinthe air passage.
 9. The tool as described in claim 8, wherein eachoutlet has an arcuate configuration, and is oriented in compatiblealignment with the direction of air flow within the air passage.
 10. Thetool as described in claim 9, wherein each outlet is progressivelyflared such that a cross-sectional area of the outlet at the spacesurrounded by the inner wall is greater than a cross-sectional area ofthe outlet at the air passage.
 11. The tool as described in claim 10,wherein the pipe has a large passage and a small passage, and the smallpassage communicates with the air passage of the head.
 12. The tool asdescribed in claim 7, wherein there are eight outlets.
 13. Incombination, a tool comprising: a connecting pipe adapted to beconnected with a hot air blower; and an annular air blowing headcomprising an outer wall, an inner wall, and an annular passage definedbetween the outer and inner walls and communicating with the connectingpipe, a circular heating space being defined inwardly from the innerwall, the head further comprising a plurality of outlets defined in theinner wall, each outlet communicating with the annular passage and withthe heating space; a package having heat-shrinkable packing material andlocated around a center of the space; wherein each outlet isprogressively flared such that a cross-sectional area of the outlet atthe heating space is greater than a cross-sectional area of the outletat the annular passage.
 14. The combination as described in claim 13,wherein each outlet is defined at an acute angle relative to the annularpassage of the head such that a direction of air flow in the outlet isgenerally compatible with a direction of circulating air flow within theannular passage to guidably attract the circulating air flow into theoutlet and result in turbulence in the space.
 15. The combination asdescribed in claim 14, wherein the direction of the air flow in theoutlet is not radially directed toward a center of the space.